====== #if constant ... #endif ======

The preprocessor directive ''#if'' will compare a constant declared with ''CONST'' to another constant.  If the ''#if'' statement is true, the statements inside the  ''#if...#endif''  block will be compiled, otherwise the statements will be discarded.

<code xbasic>
Const Device = CB280
Delay 500
' Device only returns the decimal number
#If Device = 220
 Debug "CB220 module used!"
#endif
</code>

The   above   example   illustrates   how,   depending   on   the   type   of
Cubloc/Cutouch declared, you can decide to include a command in the final
compilation of your program.  Using conditional directives, you will be able
to write applications for different Cubloc/Cutouch modules with just one
source file.

Using the preprocessor directive ''#elseif'' or ''#else'', you can create more complex ''#if...#endif'' expressions.

<code xbasic>
Const Device = CB220
Delay 500
' Device only returns the decimal number
#If Device = 220
 Debug "CB220 module used!"
#elseif device = 280
Debug "CB280 module used!"
#elseif device = 290
Debug "CB290 module used!"
#elseif device = 1720
Debug "CT1720 module used!"
#endif
</code>

''#else'' may only be used ONCE in an ''#if'' expression.  Also, you can only compare constants declared with the ''CONST'' statement in an ''#if'' directive.

Nested  ''#if''  directives are not supported;  ''#if'' may not be used inside another ''#if''.

See also [[:cubloc::ifdef..endif:|#ifdef...#ifndef]].

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